Handing over the care of a patient from one anesthesiologist to another occurs during some surgeries. A study was conducted to determine if this transfer of care might increase the risk of adverse outcomes (Jones et al. 2018). Read the excerpt from the study abstract published in JAMA below and answer the questions that follow.

Methods: A retrospective population-based cohort study was conducted of adult patients undergoing major surgeries expected to last at least two hours and requiring a hospital stay of at least one night. The primary outcome measured was a composite of all-cause death, hospital readmission or major postoperative complications all within 30 postoperative days.

Results: A total of 5941 patients underwent surgery with complete handover of anesthesia care. The primary outcome (death, readmission, or major postoperative complications) occurred in 2614 of these patients. A total of 307,125 patients underwent surgery without complete handover of anesthesia care. Of these, the primary outcome occurred in 89,066 patients. The complete handovers were statistically significantly associated with an increased risk of the primary outcome ([95% CI, 4.5% to 9.1%]; P 6 0.001), all-cause death ([95% CI, 0.5% to 2%]; P = 0.002), and major complications ([95% CI, 3.6% to 7.9%]; P 6 0.001), but not with hospital readmission within 30 days of surgery ([95% CI, -0.3% to 2.7%]; P = 0.11). 

a. Compare the percentage of each group who experienced the primary outcome (death, readmission, or major postoperative complications). Based on the abstract, can you reject the null hypothesis that there is no difference in the rates of primary outcome?

b. If you were a hospital administrator, would you recommend that complete handover of anesthesia care during operations be limited? Why or why not?

c. A difference between the two groups was found for all of the primary care outcomes except hospital readmission within 30 days of surgery. How do the confidence interval and p-values provided support this conclusion?